About 1000 learning assistants will walk out tomorrow in the first in a possible series of strikes at both additional support for learning and mainstream schools.
Leading public sector union Unison confirmed its pupil support assistant members would begin their action tomorrow in a row over pay upgrades following the requirement they administer vital medicines to pupils with needs in addition to their core duties.
The union said its members had been dismissed by Glasgow City Council and would be re-engaged on new contracts in December.
But the council said Unison had rejected its latest talks offer and accused the union of refusing any compromise.
The action is expected to cause disruption to some mainstream schools although the vast majority will be unaffected.
Councillor Stephen Curran, executive member for education and young people, said: "We are really disappointed and sorry that Unison has decided to go ahead with the industrial action which will stop our most vulnerable young people coming to school.
"We had organised another meeting today to discuss our latest compromise offer. This has again been rejected. Throughout this dispute we have listened to their concerns and offered to improve the pay of support staff. It is clear Unison is not prepared to agree a compromise which would be in the best interests of their members."
But Unison's Carol Ball said: "The council refer to asthma, diabetes, epilepsy and anaphylactic shock as 'low level' tasks and expect the lowest graded workers to undertake them. We totally reject that the lowest grade of worker should be involved in the very responsible task of administering medicines.
"The annual salary of pupil support assistants is £11,800. There has been no offer of increased pay for the administration of medicines."